Rename functions.c to lib.c. (Easier name to remember.)

1 files changed, 563 insertions, 0 deletions

diff --git a/lib/lib.c b/lib/lib.c
new file mode 100644
index 00000000..a2f1708b
--- /dev/null
+++ b/lib/lib.c
@@ -0,0 +1,563 @@
+/* vi: set sw=4 ts=4 :*/
+/* functions.c - reusable stuff.
+ *
+ * Functions with the x prefix are wrappers for library functions.  They either
+ * succeed or kill the program with an error message, but never return failure.
+ * They usually have the same arguments and return value as the function they
+ * wrap.
+ *
+ * Copyright 2006 Rob Landley <rob@landley.net>
+ */
+
+#include "toys.h"
+
+void verror_msg(char *msg, int err, va_list va)
+{
+	fprintf(stderr, "%s: ", toys.which->name);
+	vfprintf(stderr, msg, va);
+	if (err) fprintf(stderr, ": %s", strerror(err));
+	putc('\n', stderr);
+}
+
+void error_msg(char *msg, ...)
+{
+	va_list va;
+
+	va_start(va, msg);
+	verror_msg(msg, 0, va);
+	va_end(va);
+}
+
+void perror_msg(char *msg, ...)
+{
+	va_list va;
+
+	va_start(va, msg);
+	verror_msg(msg, errno, va);
+	va_end(va);
+}
+
+// Die with an error message.
+void error_exit(char *msg, ...)
+{
+	va_list va;
+
+	va_start(va, msg);
+	verror_msg(msg, 0, va);
+	va_end(va);
+
+	exit(toys.exitval);
+}
+
+
+// Die with an error message and strerror(errno)
+void perror_exit(char *msg, ...)
+{
+	va_list va;
+
+	va_start(va, msg);
+	verror_msg(msg, errno, va);
+	va_end(va);
+
+	exit(toys.exitval);
+}
+
+// Stub until the online help system goes in.
+void usage_exit(void)
+{
+	exit(1);
+}
+
+// Like strncpy but always null terminated.
+void strlcpy(char *dest, char *src, size_t size)
+{
+	strncpy(dest,src,size);
+	dest[size-1] = 0;
+}
+
+// Die unless we can allocate memory.
+void *xmalloc(size_t size)
+{
+	void *ret = malloc(size);
+	if (!ret) error_exit("xmalloc");
+
+	return ret;
+}
+
+// Die unless we can allocate prezeroed memory.
+void *xzalloc(size_t size)
+{
+	void *ret = xmalloc(size);
+	bzero(ret,size);
+	return ret;
+}
+
+// Die unless we can change the size of an existing allocation, possibly
+// moving it.  (Notice different arguments from libc function.)
+void xrealloc(void **ptr, size_t size)
+{
+	*ptr = realloc(*ptr, size);
+	if (!*ptr) error_exit("xrealloc");
+}
+
+// Die unless we can allocate a copy of this many bytes of string.
+void *xstrndup(char *s, size_t n)
+{
+	void *ret = xmalloc(++n);
+	strlcpy(ret, s, n);
+	
+	return ret;
+}
+
+// Die unless we can allocate a copy of this string.
+void *xstrdup(char *s)
+{
+	return xstrndup(s,strlen(s));
+}
+
+// Die unless we can allocate enough space to sprintf() into.
+char *xmsprintf(char *format, ...)
+{
+	va_list va;
+	int len;
+	char *ret;
+	
+	// How long is it?
+
+	va_start(va, format);
+	len = vsnprintf(0, 0, format, va);
+	len++;
+	va_end(va);
+
+	// Allocate and do the sprintf()
+	ret = xmalloc(len);
+	va_start(va, format);
+	vsnprintf(ret, len, format, va);	
+	va_end(va);
+
+	return ret;
+}
+
+void xprintf(char *format, ...)
+{
+	va_list va;
+	va_start(va, format);
+
+	vprintf(format, va);
+	if (ferror(stdout)) perror_exit("write");
+}
+
+void xputc(char c)
+{
+	if (EOF == fputc(c, stdout)) perror_exit("write");
+}
+
+void xflush(void)
+{
+	if (fflush(stdout)) perror_exit("write");;
+}
+
+// Die unless we can exec argv[] (or run builtin command).  Note that anything
+// with a path isn't a builtin, so /bin/sh won't match the builtin sh.
+void xexec(char **argv)
+{
+	toy_exec(argv);
+	execvp(argv[0], argv);
+	error_exit("No %s", argv[0]);
+}
+
+void xaccess(char *path, int flags)
+{
+	if (access(path, flags)) perror_exit("Can't access '%s'\n", path);
+}
+
+// Die unless we can open/create a file, returning file descriptor.
+int xcreate(char *path, int flags, int mode)
+{
+	int fd = open(path, flags, mode);
+	if (fd == -1) perror_exit("No file %s\n", path);
+	return fd;
+}
+
+// Die unless we can open a file, returning file descriptor.
+int xopen(char *path, int flags)
+{
+	return xcreate(path, flags, 0);
+}
+
+// Die unless we can open/create a file, returning FILE *.
+FILE *xfopen(char *path, char *mode)
+{
+	FILE *f = fopen(path, mode);
+	if (!f) perror_exit("No file %s\n", path);
+	return f;
+}
+
+// Keep reading until full or EOF
+ssize_t readall(int fd, void *buf, size_t len)
+{
+	size_t count = 0;
+	while (count<len) {
+		int i = read(fd, buf+count, len-count);
+		if (!i) return len;
+		if (i<0) return i;
+		count += i;
+	}
+
+	return count;
+}
+
+// Keep writing until done or EOF
+ssize_t writeall(int fd, void *buf, size_t len)
+{
+	size_t count = 0;
+	while (count<len) {
+		int i = write(fd, buf+count, len-count);
+		if (i<1) return i;
+		count += i;
+	}
+
+	return count;
+}
+
+// Die if there's an error other than EOF.
+size_t xread(int fd, void *buf, size_t len)
+{
+	len = read(fd, buf, len);
+	if (len < 0) perror_exit("xread");
+
+	return len;
+}
+
+void xreadall(int fd, void *buf, size_t len)
+{
+	if (len != readall(fd, buf, len)) perror_exit("xreadall");
+}
+
+// There's no xwriteall(), just xwrite().  When we read, there may or may not
+// be more data waiting.  When we write, there is data and it had better go
+// somewhere.
+
+void xwrite(int fd, void *buf, size_t len)
+{
+	if (len != writeall(fd, buf, len)) perror_exit("xwrite");
+}
+
+char *xgetcwd(void)
+{
+	char *buf = getcwd(NULL, 0);
+	if (!buf) perror_exit("xgetcwd");
+
+	return buf;
+}
+
+void xstat(char *path, struct stat *st)
+{
+	if(stat(path, st)) perror_exit("Can't stat %s\n",path);
+}
+
+// Cannonicalizes path by removing ".", "..", and "//" elements.  This is not
+// the same as realpath(), where "dir/.." could wind up somewhere else by
+// following symlinks.
+char *xabspath(char *path)
+{
+	char *from, *to;
+
+	// If this isn't an absolute path, make it one with cwd.
+	if (path[0]!='/') {
+		char *cwd=xgetcwd();
+		path = xmsprintf("%s/%s",cwd,path);
+		free(cwd);
+	} else path = xstrdup(path);
+
+	// Loop through path elements
+	from = to = path;
+	while (*from) {
+
+		// Continue any current path component.
+		if (*from!='/') {
+			*(to++) = *(from++);
+			continue;
+		}
+
+		// Skip duplicate slashes.
+		while (*from=='/') from++;
+		
+		// Start of a new filename.  Handle . and ..
+		while (*from=='.') {
+			// Skip .
+			if (from[1]=='/') from += 2;
+			else if (!from[1]) from++;
+			// Back up for ..
+			else if (from[1]=='.') {
+				if (from[2]=='/') from +=3;
+				else if(!from[2]) from+=2;
+				else break;
+				while (to>path && *(--to)!='/');
+			} else break;
+		}
+		// Add directory separator slash.
+		*(to++) = '/';
+	}
+	*to = 0;
+
+	return path;
+}
+
+// Find all file in a colon-separated path with access type "type" (generally
+// X_OK or R_OK).  Returns a list of absolute paths to each file found, in
+// order.
+
+struct string_list *find_in_path(char *path, char *filename)
+{
+	struct string_list *rlist = NULL;
+	char *cwd = xgetcwd();
+
+	for (;;) {
+		char *next = path ? index(path, ':') : NULL;
+		int len = next ? next-path : strlen(path);
+		struct string_list *rnext;
+		struct stat st;
+
+		rnext = xmalloc(sizeof(void *) + strlen(filename)
+			+ (len ? len : strlen(cwd)) + 2);
+		if (!len) sprintf(rnext->str, "%s/%s", cwd, filename);
+		else {
+			char *res = rnext->str;
+			strncpy(res, path, len);
+			res += len;
+			*(res++) = '/';
+			strcpy(res, filename);
+		}
+
+		// Confirm it's not a directory.
+		if (!stat(rnext->str, &st) && S_ISREG(st.st_mode)) {
+			rnext->next = rlist;
+			rlist = rnext;
+		} else free(rnext);
+
+		if (!next) break;
+		path += len;
+		path++;
+	}
+	free(cwd);
+
+	return rlist;
+
+}
+
+// Convert unsigned int to ascii, writing into supplied buffer.  A truncated
+// result contains the first few digits of the result ala strncpy, and is
+// always null terminated (unless buflen is 0).
+void utoa_to_buf(unsigned n, char *buf, unsigned buflen)
+{
+	int i, out = 0;
+
+	if (buflen) {
+		for (i=1000000000; i; i/=10) {
+			int res = n/i;
+
+			if ((res || out || i == 1) && --buflen>0) {
+				out++;
+				n -= res*i;
+				*buf++ = '0' + res;
+			}
+		}
+		*buf = 0;
+	}
+}
+
+// Convert signed integer to ascii, using utoa_to_buf()
+void itoa_to_buf(int n, char *buf, unsigned buflen)
+{
+	if (buflen && n<0) {
+		n = -n;
+		*buf++ = '-';
+		buflen--;
+	}
+	utoa_to_buf((unsigned)n, buf, buflen);
+}
+
+// This static buffer is used by both utoa() and itoa(), calling either one a
+// second time will overwrite the previous results.
+//
+// The longest 32 bit integer is -2 billion plus a null terminator: 12 bytes.
+// Note that int is always 32 bits on any remotely unix-like system, see
+// http://www.unix.org/whitepapers/64bit.html for details.
+
+static char itoa_buf[12];
+
+// Convert unsigned integer to ascii, returning a static buffer.
+char *utoa(unsigned n)
+{
+	utoa_to_buf(n, itoa_buf, sizeof(itoa_buf));
+
+	return itoa_buf;
+}
+
+char *itoa(int n)
+{
+	itoa_to_buf(n, itoa_buf, sizeof(itoa_buf));
+
+	return itoa_buf;
+}
+
+// Return how long the file at fd is, if there's any way to determine it.
+off_t fdlength(int fd)
+{
+	off_t bottom = 0, top = 0, pos;
+	int size;
+
+	// If the ioctl works for this, return it.
+
+	if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512L;
+
+	// If not, do a binary search for the last location we can read.  (Some
+	// block devices don't do BLKGETSIZE right.)  This should probably have
+	// a CONFIG option...
+
+	do {
+		char temp;
+
+		pos = bottom + (top - bottom) / 2;
+
+		// If we can read from the current location, it's bigger.
+
+		if (lseek(fd, pos, 0)>=0 && read(fd, &temp, 1)==1) {
+			if (bottom == top) bottom = top = (top+1) * 2;
+			else bottom = pos;
+
+			// If we can't, it's smaller.
+
+		} else {
+			if (bottom == top) {
+				if (!top) return 0;
+				bottom = top/2;
+			} else top = pos;
+		}
+	} while (bottom + 1 != top);
+
+	return pos + 1;
+}
+
+/*
+ This might be of use or might not.  Unknown yet...
+
+// Read contents of file as a single freshly allocated nul-terminated string.
+char *readfile(char *name)
+{
+	off_t len;
+	int fd;
+	char *buf;
+
+	fd = open(pidfile, O_RDONLY);
+	if (fd == -1) return 0;
+	len = fdlength(fd);
+	buf = xmalloc(len+1);
+	buf[xread(fd, buf, len)] = 0;
+
+	return buf;
+}
+
+char *xreadfile(char *name)
+{
+	char *buf = readfile(name);
+	if (!buf) perror_exit("xreadfile %s", name);
+	return buf;
+}
+
+*/
+
+// Open a /var/run/NAME.pid file, dying if we can't write it or if it currently
+// exists and is this executable.
+void xpidfile(char *name)
+{
+	char pidfile[256], spid[32];
+	int i, fd;
+	pid_t pid;
+	
+	sprintf(pidfile, "/var/run/%s.pid", name);
+	// Try three times to open the sucker.
+	for (i=0; i<3; i++) {
+		fd = open(pidfile, O_CREAT|O_EXCL, 0644);
+		if (fd != -1) break;
+
+		// If it already existed, read it.  Loop for race condition.
+		fd = open(pidfile, O_RDONLY);
+		if (fd == -1) continue;
+
+		// Is the old program still there?
+		spid[xread(fd, spid, sizeof(spid)-1)] = 0;
+		close(fd);
+		pid = atoi(spid);
+		if (fd < 1 || kill(pid, 0) == ESRCH) unlink(pidfile);
+
+		// An else with more sanity checking might be nice here.
+	}
+	
+	if (i == 3) error_exit("xpidfile %s", name);
+
+	xwrite(fd, spid, sprintf(spid, "%ld\n", (long)getpid()));
+	close(fd);
+}
+
+// Create a dirtree node from a path.
+
+struct dirtree *read_dirtree_node(char *path)
+{
+	struct dirtree *dt;
+	char *name;
+
+	// Find last chunk of name.
+	
+	for (;;) {
+		name = strrchr(path, '/');
+
+		if (!name) name = path;
+		else {
+			if (*(name+1)) name++;
+			else {
+				*name=0;
+				continue;
+			}
+		}
+		break;
+	}
+
+   	dt = xzalloc(sizeof(struct dirtree)+strlen(name)+1);
+	xstat(path, &(dt->st));
+	strcpy(dt->name, name);
+
+	return dt;
+}
+
+// Given a directory (in a writeable PATH_MAX buffer), recursively read in a
+// directory tree.
+
+struct dirtree *read_dirtree(char *path)
+{
+	struct dirtree *dt = NULL, **ddt = &dt;
+	DIR *dir;
+	int len = strlen(path);
+
+	if (!(dir = opendir(path))) perror_msg("No %s", path);
+
+	for (;;) {
+		struct dirent *entry = readdir(dir);
+		if (!entry) break;
+
+		// Skip "." and ".."
+		if (entry->d_name[0]=='.') {
+			if (!entry->d_name[1]) continue;
+			if (entry->d_name[1]=='.' && !entry->d_name[2]) continue;
+		}
+
+		snprintf(path+len, sizeof(toybuf)-len, "/%s", entry->d_name);
+		*ddt = read_dirtree_node(path);
+		if (entry->d_type == DT_DIR) (*ddt)->child = read_dirtree(path);
+		ddt = &((*ddt)->next);
+		path[len]=0;
+	}
+
+	return dt;
+}